Valve construction



Sept. 25, 1951 o. c. MARTIN VALVE CONSTRUCTION 9 Sheet's-Sheet 1 Filed June 5, 1946 INVENTOR. C. MARTIN,

deceosqd EMmer/y,

Sept. 25, 1951 o. c. MARTIN 2,569,014

VALVE CONSTRUCTION Filed June 5, 1946 9 Sheets-Sheet 2 INVENTOR.

0776 C. MAQWN,

- eceased WAe/o/v .MeT/N, 7 Amm/stratnx A Tree/v5).

Sept. 25, 1951 Filed June 5, 1946 O. C. MARTIN VALVE CONSTRUCTION 9 Sheets-Sheet 4 INVENTOR.

' Ons- CMAET/N,

v deceased 4 91444210 EJ144277,

ATTOQNEY.

Sept. 25, 1951 o. c. MARTIN 2,569,014

VALVE CONSTRUCTION I Filed June 3, 1946 9 Sheets-Shet 5 ATTOQNEY.

1951 o; c. MARTIN VALVE CONSTRUCTION Sept. 25,

9 Sheets-Sheet 6 Filed June 5, 1946 1 i w a i w w wig max , INVENTOR. 071s MAQ/O/V C. MART/N,

deceased MART/N I min/Strait Sept. 25, 1951 o. c. MARTIN I 2,569,014

VALVE CONSTRUCTION Filed June 5, 1946 9 Sheets-Sheet 7 INVEN TOR. 0776 C: MART/1v, deceased WAE/O/VAEMAEfl/Y,

Sept. 25, 1951 o. c. MARTIN VALVE CONSTRUCTION 9 Sheets-Sheet 9 Filed June 5, 1946 N dW I Rn mmwmm w. Em c N V- B ATTOQNlEY- Patented Sept. 25, 1951 Elizabeth,,N- J. j

Application jJuneffsf, 1946, Serial No. 674,0;7 H

6 Claims ..,.(Cl.

1 This inventionrelatesto valve'constructions andhas particularreference to a valve structure of "relatively small size and weight; particularly adanted for the controlof flow of fluids-in either pneumatic or hydraulic-control apparatus where space ;1imitations and-weight limitations are of importance.

In' many hydraulic g or pneumatic control systems; for example, on aircraft," th control valves to be employed must occupy a minimum amount of space and m'ustfbe -of a's-' little weight as possible and yet be capable of controlling high'rates of 110w and relatively high pressures. In 'addi- .7 tio n to theserequirements, it frequently becomes r. necessaryto-provideactuating apparatus for the valves which are to be located remote from the location of the valve itself or thecontrols for the valves must be capableof being operated from twodifferent relatively-spaced locations.

It is therefore an object "or this invention to .1

provideavalve construction in which'the-fluidto be'controlled'is controlled-directly byimain valves which are in turnactuated-by pilot valves permitting a minute amount of motion of a pilot. valve to control "a relatively great amountfiofmovement of a main valve to therebypermitw relatively large volumetricflowthrough the main Valve- I Another obj ect-of this invention -is to provide a valve construction as set forth in which the pilot; 3 valve-or valves may-be actuateimanually. at the valve location or may. ..be.. actuated... either draulically or.electriciallyirorn.iremote locations 4 Anothenobjectofcthe .present invention is tog,- providea valve constructionofthe character set forth,..in.which..a single. valve .unit maybe pro vided with... a multiplicity of, control apparatus. n permittingoperation of .thevalves from any one of .a plurality of locations.

Anotherobject of the; presentinvention is to d a o s r o whereina ne evalve 1 1... comprising main valves. and pilot valves ior. ac}; tuating th main va ves ma b ead y. d p d- I for difierent; types of -control actuation by .the. I. mer addition of the valve'unit of a'control emu-. nta i t asel fied QPf t fie i l li t ratus.

Another. objectof this. inventionis to provide a construction et forth intheipreceding parga e. wee ela i 'e e e 1 to J d with. the valve unit' may vbf a manually operated unit ,amagnetically operated-unit or a'fluidoper-i ate unit, orimay 'tain'any selected combinatioiiofls ich typesloi operators,

im 1". i fit o u... m ace i qx e a valve construction wherein-a, sing-1e valvebody' containingvalve b'ores niay' be employed to' ac complish 2 -way,f3-way o'r -vvay controlby merelyl selectingthe main'valves and pilot valves to be ix used intheas sembly." l

Another object-of this invention is to-provide. a construction of the character set'forthwvhere-l in .the'structu're' i'naybe jnianu'factured" with: a I- minimum of complicated-machining operations.

Other objects and-advantagesof thisinvention Will be "apparent fro'rn'a tudy or the'ffollowin g. specifications; read in 'coiinection with" the-ac companying drawingsj'whereinf Figyll is a 'perspect'ivewieW of a valve con structed in: accordance -'wit h this invention adapted as a 4-wayvalve'to control the operations of a cylinder and'p'ist ojn mechanism withf'which 'l' it may'beassociat'edr Fig; 2 is a horizontalsectional view-takenalongtheplanellmll of Fig'l; Fig. -3 'is'a vertials'ectional view taken alongtheline III- -IIIof Fig.2?

Fig. 4 is a vertical sectionalview take 11: alongtheline IV-lV ofFig'ffzj Fig. 5 is a vertical sectional view taken along thghnq vivpfgmgfm. Fig. 6 isahoriz'ontalsectional view through the cap of the valvetakenalongline' VI-"VI-of Fig.3," and illustrating a portion of the cap as broken T away to disclose the u'pper surface of the valve:

body disposedfbeneath th same Fig. 7 is a vertical sectional'view through the cap. and a portion ofthe valve 'body taken alongj line VII V'II of Fig. 6; Y

Fig. 8 is a verticalsegtional View through the cap and handle structuretaken-along j line-VIII; VIIIofFigi'Ti Fig. 9 is a vertical sectional view taken along line; IX -IX of Fig.2) 1 r Fig. 10' is aschematic view of the valve structure illustrated Figs. 1 tl'irough'9 andillus trating "diagrammatically" the relative-positions oithe'parts when th'eval'veis idle;

Fig. 11 is 'a 'schmatic viwsiinilar-to-Figlo and illustrating-the relative positions or the .partsi when the'v'alveis actuated tc'uause fluid to fiow Fig'. 13 fragmentary rrnt 'ev'atioiial view of car ier control un t /men ma'ybe applid to'the' valvebo dy'illustrated 'Figs'fl through in substitution for the manually actuatable unit shown in Fig. 1;

Fig. 14 is a bottom plan view of the control unit shown in Fig. 13;

Fig. 15 is a perspective view similar to Fig. 1 but illustrating the valve unit as having associated therewith a control unit including both a. hydraulic actuator and a magnetic actuator for the valve;

Fig. 16 is a bottom plan view of the control unit shown in Fig. 15;

Fig. 17 is a vertical sectional View taken along the plane indicated by the line XVII-XVLI of Fig. 15;

Fig. 18 is a horizontal sectional view taken along the line XVIII-XVHI of Fig. 17;

Fig. 19 is a vertical sectional view taken along the line XIX-XIX of Fig. 17; and

Fig. 20 is a horizontal sectional view taken along the line XX-XX of Fig. 17.

Referring to the drawings, there is illustrated in Fig. 1 a simple adaptation of the valve to a hydraulic control problem wherein the valve unit designated generally by the reference character A is associated with a hydraulic control cylinder K, the piston of which (not shown) is coupled to a piston rod L which is adapted to be reciprocated relative to the cylinder K by the flow of fluid in either of two directions, namely, through a pipe M into one end of the cylinder, while fluid is exhausted from the other end of the cylinder through a pipe N or vice versa.

The valve structure as illustrated in Fig. 1 comprises a valve body I containing the various main and pilot valvesrequired to cause the fluid to flow in the desired direction through the pipes M and N and which in the form illustrated is a 4-way valve unit wherein pressure from a, suitable pressure source is admitted into the valve unit I through a pipe 2 while fluid from the system is either exhausted or is directed to a fluid return line through a pipe 3. y

By referring particularly to Figs. 1 through 6, it will be observed that the valve body I comprises a substantially cubical block of metal, into one end of which extends a pressure receiving port 4. to which the pressure supply pipe 2 may be coupled by means of any suitable tube or pipe fitting well known in this art. For convenience of illustration, the pipe lines are illustrated as smooth-ended metal tubes of the type commonly employed in the hydraulic systems of aircraft while the fittings or couplings employed are illustrated as the conventional tube fittings 'employed in aircraft hydraulic lines.

The valve body I is also provided upon its opposite end with a, return port 5, which as illustrated in Fig. 1 is coupled by means of a suitable fitting 6 to the exhaust or return pipe or tube 3. From the under side or bottom of the body I there extends two ports I and 8 which may be referred to as the cylinder ports, the port I being connected by means of a fitting 3 to the pipe M leading to one end of the cylinder K while the port 8 is connected by means of a fitting In to the pipe N communicating with the opposite end of the cylinder K.

By referring particularly to Fig. 2, it will be observed that from the top surface of the body I there extend six identical bores PB, RB, CB, DB, EB and FB, said bores extending from the upper surface of the body I as a bore of one diameter with a continuation of each of the bores at a lesser diameter as indicated in Fig. 3 at 11. Each of the bores, however, is provided between its 4 larger and lesser diameter portions with enlargements, one of which is indicated at I2 in Fig. 3, causing that particular bore to be intercommunicated with others of the bores, as will be more fully hereinafter described.

Likewise the lower ends of each of the bores communicate with certain ofthe ports 4, 5, 'I

and 8, respectively, through the medium of enlargements of the bores comprising these ports, one of which is indicated at I3 in Fig. 3, so that each of the several bores FB, PB, CB, DB, EB

, and RB is properly communicated with the ports necessary to permit the flow of fluid from the pressure line in one direction to the cylinder K or in the other direction to the cylinder K while the return fluid from the cylinder K is properly directed to the return line 3.

Again referring to Figs, 2 through 5, the intercommunication of the various bores PB, RB, etc. is as follows: The bore PB communicates at all times with the pressure inlet port 4, by reason of the intersection of the downwardly extending reduced portion PBI of the pressure bore with the inner end of the pressure port bore 4 which, as pointed out before, extends from the rear face of the body I and, as illustrated, the outer portion of the pressure port 4 is formed as a tapered threaded bore for the reception of the tapered threaded tube fitting required to connect the pipe 2 thereto. Thus the pressure bore PB is at all times filled with the fluid (which for purposes of the following description will be assumed to be a hydraulic fluid or liquid) and at the pressure of the supply system which supplies pressure fluid for the operation of the piston and cylinder mechanism K. The pressure bore PB likewise communicates with the two adjacent valve bores CB and FE, this intercommunication being accomplished by enlarging one or both of these bores until the enlargements intersect each other sufficiently to provide a relatively large fluid passage therebetween. As illustrated in Figs. 1 through 5 and 9, both of the adjacent bores are provided with enlargements though it will be understood by those skilled in this art that the pressure bore PB alone may be provided with a sufficient enlargement to intersect the larger diameter portions of the adjacent bores CB and Similarly the return bore RB communicates with the return port 5 by reason of the intersection of the vertically extending reduced diameter portion RBI with the laterally extending return port bore 5 which, like the pressure port I, has its outermost portion formed with a tapered thread to receive the tapered threaded tube fitting 6. Also the return bore RB is intercommunicated with the adjacent valve bores EB and DB by reason of the enlargements RBZ with corresponding enlargements of the adjacent bores EB and DB, as indicated particularly in Fig. 3, and

which from the standpoint of construction of the valve body is a duplication of the arrangement shown in Fig. 5 for the pressure bore PB merely reversed. Thus at all times the return boreRB is open to the exhaust or return line 3.

The valve bores CB and DB are at all times in communication with the cylinder port I to which the fitting 9 and pipe M are connected, the communication being established by reason of the disposition of the vertical axis of the cylinder port 1 approximately midway between the vertical axes of the adjacent bores .03 and DB and having at least a portion of the port bore 1 5 1;; of sufilcient diameter, as indicate'd at l'-3 in Fig. to intersect the reduced diameter-portionsflB andDBl "of the"correspondingvalve *bores.

Asillustrated particularly-"inFigr'3, -the cylin-* der port bore" -1 extends--from the --underneath -5 surface "of the body las a "tapered threaded-bore Y3 adapted to receive'the fittings "but the innermost end 'ofthe bore 1 is enlarged as indicated at l3 3 to achieve the -interc'ommunication justdescribed. l

correspondingly; the-=cylinder-'-bore *8 -inter-'-*- communicates-at all times-"with the reduce'd e diameter portions 'of the'valve'bores FB and-EH? by'reason'of the-enlargement of'the inner-"end of thecylinder-portbore V is It will be observed from the*foregoing descriptiorithat the construction of*'the-entire'body I'- with its various bores "PB; RB; CB; DB, EB; andtheir enlargements-"and the ports 4;-5,-1 and"8 with their-enlargements" necessary to'-20 achieve the above describedintercommunication between the various bores; may be readily accomplished by extremely *simple' machining "operation's,"the' entire body being readilyformed upon' with'indexing mechanism forcentering the variousbores, drilling tools todrill the various bores, undercutting tools to undercut 'theenlargements and threading mechanisms to thread the ports 4, ;l'and'8.

With the constructionthusfar -describedit will" be apparent thatwith'main' valves inthe"valve"" bores CB,'DB, EB and EB adapted tobe-normally closed, the fiuid pressureentering the valve through the port 4 and beingdistributed -fromthe pressure bore *PB will 'be prevented by the valves in the valve bores SB and-FB from passinginto either of the cylinder ports 1 and 8 while, though the return bore BB is open to the return line 3, the valves in the valve bores DB- and EB will prevent the passage of fluidlfrom the cylin der K to the return bore RB and its associated return port 5. Thus the bores PB and RBare not provided with valves and serve insteadiaslfluid distributors.

The construction of the valves-in the valve bores is illustrated particularly-in Figs. 2, 3, 5 and 9, it being understood that each of these'valves, is identical with the other so as to facilitate the assembly of the valve units and the ready replacement of any of these valves merely by substituting a new identical part. Therefore for purposes of convenience in this description, vthat particular 'main valve which is associated with each bore will be identified with the bore which it is located, the main valve in the bore CB bearing the number CV, the valve DV being located in the bore DB, the valve EV being located in the'bore EB, and the valve FV being located in the "bore FB. Thus but a single one of these main valves need be described.

Referring particularly to Figs. 2 and 5,'it"will"" be observed that each of the main valves EV, FV is formed as a cylindrical piece of metal, the-low er end of which is preferably chamfered asindi cated at M to form a beveled seatingsurface adapted to seat upon the shoulder 15 formed at the junction of the upper large diameter'portion of the associated valve bore, for example EB, and theilower small diameter p ortion EB l.

Thus the chamfered valve end forms its own valve seat in its particular bore and any wear' which may be occasioned by the'operation' of the main valve will merely increase the area' of con tact 'between the main: valve: and itsu'seating sur facein the body wSpaced upwardly.:fronrsthe 2;- chamfered portion ld of the main valve ini anannular groove 4 6- in' whichis seated an :annularaiv packing ring 'lpreferably formed of'neoprene oft;- the -dbnut type, '=-that -is, the packing ring com-,1; prises-an annulus of circular cross-sectioned maeateria-l 'having a cross sectional -diameter just-n. slightly in excess: ofthe depth :of #the: groove I 6 to form a' seal between the upper large diameter:

portion of the valve bore, for 'example -EB and the fvalve EV; The vertical distance between the chanifered end l4-=-and -thegroove 6 is such that when 'the valve'EV is upon its seat .15, their, packing ring I twill be disposedin the upperporzltion 'of the valve bo're EB- above the enlargement EBz of that bore. Immediately "above the packeing ring l 1 there is a shallow -but long annular groove-- 18 extending about the valve EV to pro-w" vide'aspac'e into which the pressure fluid may enter, the flange l9 between the upper-end -of:the1-- grooved-8 and.:th'e extreme upper end of the valve EV being milled away-as indicated best in Figz 6 at 20,- and in Figs. 5 and 6 at 20,: providing ready' 'communication between the space above thea simple engine lathe or turret lathe equippedfi a V fid o velfl- Thus'if the main valves CV, DV; etc., are .to be of thenormally closed type, and is illustrated:- herein these valves are held in their-normally closed positions merely by permitting the pres sure'flu'id to exert its forceupon the upper end of each of-thesevalvesand to'fill and maintain such pressure within the groove. l8. By reason of the difference. in-the area-betWeenthe upper end of each of these 'valves' and that area which is 8X1 "posed to the lowermost or reduced diameter portion the fOrce-of the pressure fiiiidfromabove the main valves and the-forcesthen exerted upon the chamfered end of the valves will cause-them to 2 rise within their bores:

While,- aspointed" out, the differencein theareas of the valve portions Which-are exposed to the fluid pressures will under ordinary conditions be'su'flieient tomaintain the valves in their closed positionand tourge them towardrftheir closed positions wheneverthe 'fluid pressure :is exerted upon the upper-portions of the valveslwithout the necessity-of utilizing any additional spring forces, 7 it may bedesirable asa matter ofsafetyorprel caution to provide those'two valves CV and FV, which areno'rmallyexposed to the pressure bore -PB,' with* the biasing springs 2| which may be,'as, vI illustrated :in Fig's. 5"and 9;merely'he1ical springs disposed in' a central-counter bore 22- extending from-:the'upper end 'of'each'of the main valves CV.1

Since the valves are preferably to be identical in structure; all'of the bores are preferably bored but=springsare located only in the two valves CV-- The valves DV- and EV, when closed, having: their lower portions exposed only tothe" 1static forces of the static liquid in thecylinder K,'

neednott be provided with springs but can be urged toward their-closed positions'merely by the" application of fluid pressure: to the "upper ends'of the valve's'; I 'I'o cause the selective lifting or the -main valves-FV-and-DV, When-it is desired for the pistoni rod-L to be moved outwardly 0f the cylinder K, it is only necessary to relieve the nor- 5 mal fl-uid pressure' uponfthe =upprends= of these 76::two ya1ves while fluid pressure- 1s maintained u on the upper ends of the remaining two valves CV and EV. Likewise to cause fluid to flow in the opposite direction to the cylinder K, it is only necessary to relieve the fluidpressure upon the upper ends of the valves CV and EV while maintaining the fluid pressure upon the upper ends of the valves DV and FV. To accomplish.

this selective control, there is utilized a pilot valvestructure illustrated particularly in Figs.

2, 4 and 9 through 12.

By referring particularly to Fig. 2, it will be observed that the various bores PB, RB, CB,

- valve body having a reduced diameter portion which extends into and fits within the pilot valve bore PVB but does not quite reach the bottom of the pilot valve bore. Intermediate the upper end of the pilot valve bore and the bottom of the pilot valve body, the surface of the body is formed with a plurality of grooves 25, 26, 21, 28, 29. 30 and 31 which for convenience in manufacture may be of identical shape and dimensions, the uppermost of these grooves 25 being a packing groove in which is disposed a donut packing ring 25a, the function of which is that of a sealing ring as was described with reference to the packing ring 11 for each of the main valves.

Likewise alternate grooves 21, 29 and 3| are provided with packing rings sealing the remaining alternate grooves 26, 28 and 30 from intercommunication with each other. Thus the pilot valve body may be readily formed as a separate unit with its packing rings associated therewith and then be merel pressed into the pivot valve bore PVB with assurance that each of the grooves 26, 28 and 30 will be isolated from each other.

As will be most readily observed from an inspection of Fig. 9, a pair of pilot valve chambers 32 and 33 are formed through the pilot valve body 23, each of the chambers comprising an upper bore 34 and a lower bore 35, the lower bore being of slightly greater diameter than thatv of the upper bore, the two chambers 32 and 33 extending parallel to each other, one disposed upon each side of the vertical center of the pilot valve body 23. In each of the bores is a pilot valve structure which preferably comprises an upper pilot valve member 36 and a lower pilot valve member 31. The upper pilot valve member 36 (see Figs. 9 and is formed as a cylindrical member having a valve head 38 formed upon its lower end of a diameter in excess of the diameter of the upper portion 34 of the chamber 32 while immediately above the head is an annular groove 39 providing a fluid passage about the valve member 36. Immediately above the groove 39 the valve is formed with a cylindrical surface having a diameter fitting the diameter of the upper portion 34 of the chamber 32, a packing ring 40 being disposed in a groove 4| to seal against the leakage of fluid from the valve member 36 to the exterior of the pilot valve body 23.

The lower pilot valve member 31 is formed with an enlargedhead 42 adapted to abut the,

lower surface of the pilot valve body 23,- a pack H portion 35 of the chamber 32 to seal against inadvertent leakage of fluid downwardly past the valve member 31. Immediately above the packing ring 43 the diameter of the valve member 31 is reduced to provide a fluid passage about this member to permit the ready passage of fluid upwardly and downwardly alongside this valve member. The upper end of the lower pilot valve member 31 is counter-bored as indicated at 44, leaving an upstanding flange which constitutes a seat against which lower chamfered surface of the head 38 formed upon the upper valve member 36 may seal. Thus if fluid pressure from the source is permitted to flow into the lower end of the pilot valve bore PVB, such fluid may then flow upwardly through a central counterbore 45 in the lower valve member 31 into the counter-bore 44 and outwardly between the valve members 36 and 31 and about the exterior surface of the lower valve member 31 and into communication with a port 46 which communicates thechamber 32 with the lowermost free groove 30 on the exterior surface of the pilot valve body 23. Also such fluid pressure will push upwardlyupon the lower end of the upper pilot valve member 36, causing the upper chamfered surface of the head 38 to seal upon the shoulder 41 formed between the two different diameter bores forming the chamber 32.

To overcome the slight friction which may be occasioned by reason of the bearing of the packing rings 40 and 43 upon the chamber surfaces, it is preferred to normally urge the lower pilot valve member upwardly by means of a spring 46 which has one of its ends bearing upon the lower surface. of the pilot valve bore PVB and its upper end extending into the counter-bore 45. Similarly the uppermost valve member 36 is normally urged into seating relation with its seat 41 by means of a spring 49, one end of which bears upon the lower member 31 and the other member extends into a counter-bore formed in the upper end of the lower valve member 36.

The other pilot valve is of identical construction and need not be re-described though for purposes of convenience for the following description the pilot valve assembly which has been described in detail will be referred to as pilot valve R while the other pilot valve assembly will be referred to as the pilot valve S. It will be noted, however, that fluid pressure applied to the underneath surface of the pilot valve S will flow upwardly through the interior of the member 31 of this valve and out through the space between the upper member 36 and the lower member 31 and about the reduced diameter portion of the member 31 and through a port 50 into communication with the intermediate free groove 28 of the pilot valve body 23 while at the same time the fluid pressure will be applied to the underneath side of the upper valve member 36,. maintaining this valve closed against its seating suriac in the pilot valve body 23.

It will also be observed that the uppermost free groove 26 of the pilot valve body is at all times communicated with the grooves 39 in the upper valge members 36 of both of the pilot valves. R an S.

To maintain the pilot valves in their normal 1 positions as shown in Figs. 9 and 10, fluid pressure I I 9 miserab ou h, the m dium .o a i o valve checkvalve PVX, the location and construction mof which is best illustratedin Fig. 4 wherein this .check valve is illustrated as a cylindrical valve ---observed that the mainvalvebore DB intercom- --municates with the lowermost of the grooves 38 in the pilot valve body-by means-of a milled passage- 51 at the same level intercommunicates this same groove 30 with the main valve bore FB.

By forming diametrically opposite milling cuts 58 and 59 at the intermediate level, the main ,member extending into a vertical bore PVXB valve bores CB and EB are communicated with which in turn extends from thebottom of the the intermediate level groove-28. ,,pilot valve bore .PVB downwardly past the en- The construction of the pilot valve assemblyas largement P132 ofthe pressure bore PB. hereinbefore described is such that it, likethe ,The pilot valve PllXhas a valve head 5| main valve body I and the main valves CV, DV, adapted to seat uponvthe should'er formed by the etc., can be constructed entirely by enginelathe junctionof thelower end of the pilot valve bore operations or screw machine or turret lathe op- PVBr andwthe check valve bore PVXB. The erations since each of the parts is cylindrical-in intersection of the check. bore PVXB with the shap r q g the use of no other tools. enlargement BB2 exposes the bore PVXB con- With the main and pilot valve constructions V stantly to the pressure fro the pressure supply thus far described, the complete operation of the line so that liquid will flow into thepilot valve valve structure as a four-way valve may be best bore PVB until the pressure therein is .equal to O y n o th di r ic 0D- t Pressure 0f t ZSBPQIY line, whereupon the erati onal Figs; 10, 11 and 12. The valve body l is Qcheckvalye willclose aided by means of aspring gr m c illustrated as being provided '52, hi h t d i tq gountepbore in th fl t go with the pressure inlet port 4, the two cylinder 1 valve PVX andhas .its upper end bearing agains't'- ports I and 8 and two'return ports 5, one at each .wthe lowerend of'the pilot valve body 23, side of the body I. It will be understoodthat this Also whenever liquid mello d t flow th is merely a convenient representation of the th 11 1; alve assembly, th e t mp single return port 5 in the actual valve construcsur e in the,pilot valve ,bore PVB will allow the v tion since the radial construction has been split n check valve to open t re pl enish thi 1y b at port 5 and developed as a planar valve arrangethat t anmtimesug pteshsur'e is maintained on ment for purposes of exposition. Likewise the t pilot yalvq asysremblyelqum 't u in milled cuts 53, 56, 51, 58 and 59 are represented by I, the supply uneh Further; in the event the supply elongated pass leading f e p op vel wlinersho'uld break e bressure in Supply, of the pilot valve bore PVB to the respective bores ,line should otherwise be reduced, the check valve h which t e Cuts communicatebvvill act ,to m aintain a relatively high pressure 10 the position of all t hee e parts within the pilot valveassembly and abov each of of the valve structure are shown in their normal .;the main valves soastoinsurethat,these valves no d pqsittons' t when an otfthe will .remain closed; Thus, r d cti f 1 f main valves are closed and the cylinder and piston pressure in the supply, line will: not result. in any me s is at f 1 this Po i th liq id movement or change of position of the pistonrod e e n t t' s Port 4 Passes to theptessure .L, the check valve act ng as a safety device to whore PB and em b Way f enlargement maintain the positions of the; a p ra PBZ to the main valves'CY-and EV. Likewise this ,trolled by the valve, structure until the supply :0 liquid communicates Ql h h? D Valve Check pressure has been restored, bore PVXB and through the pilot valve PVX to Byreferring particularly t Figs 2, 4 and 9, t thepilot valve bore PVB and thus to the under side will be observed that the port 46in the pilot .Q the P t. assemblies R and With the V valve body 23 which communicates betwe th pilot valve assemblies R and s in their normal pojl t al Rand th n i' g t a sition; as shown in Fig. 10, theeffect of the ,lower level than the'portfill which" communicates gp es n the'pilot Valve bore PVB will be with the pil t' al s Al dit fll bgpbserved to hold the upper valve members 36 of each of that the grooveflfi on the pilot t alv b d i prothese valve assemblies in their uppermost or closed vided with two t sa and 54 hi h t mm positions. Thus the'fluid pressure passing up A Cat b en the groove; 6 and each of th fl t 50 through the lower pilot valvemember 31 will pass 7 valves R and S, 1 espectivel y, at a stillihi gh OUtWardIy through the port 50 intothe annular level, the communication 'with th pi'lot 'tal space defined by the groove 28 and thenceby way b nee v t ee t th u permost eleof the milled cut'56' to the upper end of the main A merit of each of these pilot valves; valve DV, applying fluid pressure above this valve, t il l alsonbe Q dt 't by reason f t holding it closed against its seat. At the same v j location of thegrooves g5, 28 and Bll at the u time the fluid pressure will pass through the diaes i e v hig r l vel in ercofinnunication bemetrically opposed milled cut 51 to the upper side tween them and the respective main valve bores 0f the main valve FV, holding this valvein its 7 may readily be accomplished merely by formin a closed position. Likewisethe liquid passing up ,gcutz a a y hrO gh., he material ofrthe valve 0 through the lower valve memberof the valve asi qdy l tointersectthe respective valve bores. sembly R will hold the upper .valve member of this By referring to Figs. 2 and 4, it will be noted that assembly in its closed position while the fluid 3 the return bore RE is intercommunicated with the pr sure w ll pass t ue h p rt 46 i to th anuppermost groove 25 of the pilot valve body by T111191 p provided b groove 0, from I r 1eans'of a passageway55 which may be formed whence Such fluid pressure-will pass through the as a milled cutextended from the ilot va1ve b re milled cut 59 to the upper side of the main .valve toward and into the return bore RB, such milling EV,-.holding this valve in its closed position while I out being made by a suitable narrow circular millat the same time such fluid pressure will pass --i ngcut ter or in any other desired manner. 1 through the diametrically opposed milled cut 58 to Likewise, by referring to Figs. 2 an d 9, itwill be the upper side of the main valve CV, holding this valve closed.

Thus all of the valves are held closed by the ssh-rot the pilot valve bore acorresponding milled cut 7 V will be permitted tofiow througheither of the cylinder ports 1' and 8 nor. will fluid be directed to --=:way55-while on the diametrically opposite side in Fig. 11, whereupon all of the parts will assume the positions diagrammatically illustrated that 1 figure. The depression of the upper valve member 36 of the pilot valve assembly R will causethe upper valve member to leave its seat 41 and thus permit the fluid pressure which has been exerted upon the upper ends of main valves EV and CV to be relieved, the liquid above these valves being permitted to escape back through the milled cuts 58 and 59 t the annular space provided by the groove 30 in the pilot valve body,and thence upwardly alongside the lower valve member 31, past the upper, valve member and outwardly through the port 53 and the annular groove 26 of the pilot valve body, and thence through the milled cut 55 to the return bore RB and to the return port 5, and thence to the return or exhaust line 3.

Release of pressure upon the upper sides of the valves EV and CV permits these valves to be pressed upwardly by reason of the pressure or the pressure fluid exerted upon the lower sides of the valves, the valve CV being lifted from its seat by reason of the fact that the fluid pressure from the pressure source passing through the pressure bore PB is applied to the under side of the valve CV and will lift the sameas soon as pressure above this valve has been relieved. Thus the valve CV rises from its seat and permits the flow of the pressure fluid from the pressure bore PB through valve bore CB and thence through the cylinder port 1, pressing the piston rod L toward the left 'as viewed in Fig. i. The fluid on the opposite side of the piston is thus urged outwardly through the pipe N and into the cylinder port 8 where it presses upwardly on both of the main valves EV and FV. The valve FV, having the full fluid pressure upon'its upper side as well as the lower side, will remain on its seat while the valve EV, having the pressure on its upper side relieved, will rise on its seat and permit the flow of the fluid from the cylinder K to pass to the return bore RB and through the return port and return line 3. Thus the piston rod L will be moved toward the left, as viewed in Fig. 1, until it has reached a desired position, whereupon release of the pilot valve R will cause the pilot valve to close upon its seat 41 and the pressure of the pressure fluid is again built up above the valves EV and CV, forcing them down upon their seats and stopping the further flow of fluid to and from the cylinder M.

Likewise, if it is desired to move the piston rod L in the opposite direction, direction of the valve assembly S will cause such a reverse operation as illustrated in Fig. 12, wherein thefluid pressure from the source entering through the pressure port 4 and upwardly past the check valve PVX will, as hereinbefore described, hold all of the main valves in their closed position but depression of the pilot valve assembly S will open the passageway past the upper valve member 36 of this assembly and thus permit the fluid pressure which has been exerted upon the main valves EV and FV to be relieved, the pressure upon the upper surface of these valves passing through the milled cuts 56 and 51 to the annular groove 28 and thence through the pilot valve port 50 and upwardly past the upper pilot valve member 36 and outwardly through the pilot valve port 54, and through the milled cut 55 to the return bore RB and the return port 5 and thence to the returmor exhaust line 3. V

The fluid pressure from the source which hasbeen impinging upon the lower sides of the valves FV and DV will therefore cause these valves to= rise. The fluid pressure passing through the pressure port 4 and to the under side of the main valve FV will thence pass through the now open Valve and into and through the cylinder port 8 to apply fluid pressure to the left-hand end of the piston in thecylinder K, urging the piston rod 11' toward the right while at the same time the fluid upon the opposite side of the piston will be forced outwardly through the pipe M and into the: cylinder port I and thence past the now open valve EV through the return bore RB to the return line 3.

Again when the desired amount of motion in that direction hasbeen achieved, release of the pilot valve assembly S" will permit the pilot valve structure to close, thus restoring the pressure to the upper side of the main valves FV and DV, closing these valves while at the same time the main valves CV and EV will remain closed and further movement of the piston rod L is arrested.

It will be observed therefore that a relatively minute amount of movement of the pilot valve assemblies R and S is required for the operation of the main valves controlled by them and that the use of merely two pilot valves will cause the selective simultaneous operation of their associated main valves, namely, the operation of the pilot valve assembly R will instantly control the movement of the main valves EV and CV while movement of the valve assembly S will control instantly the movement of the main valves FV and While it has been illustrated and described in the foregoing the adaptation of the valve structure to a normally closed type of valve wherein the main valves CV, DV, etc. are normally held in their closed positions, it will be apparent that the same arrangement may be utilized for a control, wherein it is desired that the main valves be in normally open position and merely moved to closed positions as the valves are operated, the only distinction being that the pilot valves shall operate to normally expose the upper surfaces of all of the valves to the return line except when one or the other of the pilot valve assemblies is depressed and merely requires the reversal of the pilot valve assemblies.

Likewise it will be observed that while the foregoing description has been concerned with a four-way valve structure, it will be equally apparent that one of the pilot valve assemblies and a single one of the main valves may be utilized for a two-way valve application wherein the valve is to be either opened or closed selectively upon the operation of the pilot valve. Likewise it will be apparent that the adaptation of the system of the present invention to a three-way valve arrangement may be readily accomplished by utilizing the two pilot valve assemblies and only two of the main valves, for example, either valves CV and FV or DV and EV.

Thus it will be evident that a single valve body I may be made up in stock quantities, a

number of main valves which are identical in construction may be made up in quantities, and a number of pilot valves and pilot valve assemblies may be made up in stock quantities and from such stock the number of pilot valves, main valves, etc. may be selected to be assembled for any or the desired operations.

13. Another item 'ofl interest: at thisi point is zithat repairs to the va1ve::structure may bec readily made-merely by pulling outa'worn or defective and loWer pilot valve members piloti valve body and a supply of packing rings forth'e main valves and the pilot valves."'Thisdsanitem of consid- ",uthe pilotzvalvezbody extends andr-within :which it maybe sealed againstaleakagmby means of a .suitable packing ring 61.;dispose'd inran annular groove '68.;formed about the. projecting head-24.

.Whileithe rod 63,:may .be retainedwithin its :bore in any suitablemanner, one simple form of -::retention:is illustratedzin Figs. 6, 7 and 8:as. com- :prisingl-axrelatively: thin shim 69 .adapted to be zipressed into amilled cut l extending fromthe erable importancaboth in the mass'production and also in the maintenance of:suchwalves, particularly intheir application-to aircraft where access to a large-supply of different: stock partsv may be difiicult.

In view of thefact' that the entireeoperation of this valve construction'dependsmpon the depression of one or the other of the'pilot-assemblies R ands through but a minuterfraction of an inchnecessary to open the 'upper "pilot valve members -35, the valv'e structure-may be controlled in any one'of a number of-manners, dependent'upon'ithe location of the'valve 'With respect to its accessibility'by' an operator or the necessity for providing acontrol of the valve structure from two or more locations ortthe desirability of utilizing 'two' or more "types of operators for the valvessuch as manual andfiuid pressure operations; manual and magnetic operations or any combination of'these three.

The valve structureis: therefore re'adily'adapted to the use of any "of* these by -the 'mere'selection of one of a'plurality of cap members Z to be associated with the valve-body l.

As'illustrated in Figs. llthrough 12, the operation of' the valve is by manual control; such "-control being accomplished by thelutilization of a relatively thin cap member *60 *havinglength and. breadth conforming 'withI the length and breadth of thevalvebody -I so thatwhen placed upon the valve body I' 'a'nd' secured thereto by means of suitable: screws 6l,*the"cap and its operating mechanismare 'operativelyfiassembled uponthe body I.

" *Ihecapmemberi'fifl is provided with a later-ally T extending bore 62 extendingwfrom'one of itsside surfaces, into which projects. a'valve operating 1 met es preferably ofQcircular :cross section; the

:-lower surface of thecap 69, the shim having'aslot H .th'ereinadapted to pass about theishaft .63 at a'sreducedportion thereof such as may be formed 1by cutting. an. annular groove'IZ aboutthe. shaft. Thus the shim BS'may make a'pressed fit in its cut-sand lwhen thexcap 6B is in place upon-:the

-z-:valve:body l -the inadvertent displacement or. the .shimrwill be effectively. prevented.

. By referring particularly to Figs. 3, 4,5 and 9,

t itwillbe noted. that leakage of fluid between. the

valve body 'I andthecap Bil-may be readilyxpreh'ventedby forming on'the. under surface of the .fcap"60iannu1ar grooves 6%, one for eachof- Lthe .bores PB; RB, .CB, etc., in the valvebody I, each iofsuch grooves being. concentric with but slightly larger in diameter than the diameter of the upper ends of each of hthesezbores so. thatby employing a packing ring 5690 in eachof these grooves not only is thecap efiectivelysealed-upon the body I tively sealed against leakage betweeneachxother past the meeting face of the cap 60.

outer end'of which is secured to asuitable handle 54; The round stock of therod :63 is 'milled or cut away substantiallyto the longitudinal: center plane of the rod, asindicated'at'65 in *Fig. '7,

1 so that the fiat'under surfaceis presented'immediately above the pilot valves Rand S;

- As illustrated in Fig. '6; the disposition of the bore 52 and theoperating -r'od'63 issuch that the flat surface of the'r'od is disposed 'abov'eboth of the pilot valve assembliesR and Sand, as viewed-in Fig. '7, the pilot valve assemblies project-upwardly above the upper surface of the pilot :valve body- 23 into relativelyf-z close relation To adapttthe valvestructur'e ihereinbefore described for other operations, such as a pneumatic or hydraulicactuationiofithe pilotavalve's Rand these bores'extending'on the guide to: the upper surface of the cap 66a. Infeachof. the bores I3 and =14 thereris' located a relatively'shortpiston 13a.and"14a', respectively, the lower ends'of 'the pistons projectingthrough the lower ends of-the ,.b0res '13;- and'l to restupon the upper'ends of the pilot valve'assemblies R and S. Extending laterallyfrom' oneface of the cap 1260a is a pair of threaded boresT5 and 16, each adapted to receive a threaded pipe fitting which may be coupled to a pair of hydraulic or pneumatic control tubes (not-shown) extending to'any desired-locations remote from the location of the valve structure. "From the bore 15 to the upper with the fiat surface of the rod. "Thus by partially rotating the rod 63"by' the-handle 'fi l in one direction, say clockwise,- the' -fiat surface of the rod will act as a cam engaging and depressingthe pilot-valve assembly 'S'while rotation of the rod in" the opposite directionwill causethe fiat surface to engage and depress-the pilot valve assembly R.

"It will be observed from an inspection of Figs. 6 and '7 that the underside of the cap fifl is formed with an upwardly extendingbore fifi} the-diameter-of which is-substantiallyequalto theidiameter 'of the-head-Mpf the-pilot'v'a-lve body-23; this borecomprising a seat into which 'the head 24 0f end 'ofthe piston b0re'13 there extends a port 11 'Whilea similar port 'lfi extends from the bore 16 to the upper endof the piston bore 15. Thus by applying pressure to the pipe lineleading tothe fitting bore 15, pressure is exerted upon the upper side of the piston-l3gz', depressing this piston-and. causing corresponding depression of the I pilot valve assembly R, with the resultantoperation of the main valves in the same manner as was described for the manual operation of the pilot valve R. Similarly, exertion of fluid pressure through the fittingbore '15 will cause the piston 14a to move'-downwardly, depressing. the pilot valve assembly Sto cause a reverseoperation of 'themechanism "tO be controlled by the tyalve structure. r

the fluid pressure upon either of the pistons 130.

or 14a may be of any selected type such as a manually controlled push button or a remotely controlled pair of valves in the pipe lines leading to the fitting bores 15 and 18, as will be readily understood by those skilled in this art. In view of the fact, however, that the amount of movement which is required of the pilot valve assemblies R and S for successful operation of this valve structure, it will be apparent that a relatively minute amount of fluid is actually required to be transferred through the pipe lines in order to cause a movement of the fluid actuated pistons 13a and 14a. This permits pipe lines of relatively small diameter to be extended to the remote locations, a feature which is of particular importance in the adaptation of this valve structure to aircraft in view of the fact that minute pipes of very little weight may be employed to extend the point of control of the valve structure to any desired remote location upon the aircraft.

It may be desirable to provide a remotely controlled electric control apparatus for actuating the pilot valve assemblies R and S, one form of which is illustrated in Figs. 15 through 20, which electrical or magnetic control may be utilized independently of or in combination with a hydraulic control such as that just described and the combination of the hydraulic and magnetic controls are illustrated in Figs. 15 through 20, though it will be understood by those skilled in this art that the hydraulic control may be readily omitted from the structure or while the apparatus therefor may be included in the structure it does not have to be employed but may be plugged ofi, if desired.

In Figs. 15 through 20 there is illustrated as one form of such electrical control a cap member 88 which may be substituted for the manual control cap member 68 illustrated in Fig. 1, the cap member 88 having a length and breadth conforming with the length and breadth of the valve body block A and having a height suflicient to enclose a pair of electro-magnets 8| and 82 (see Fig. 1'7),

each of which is adapted to operate one of the pilot valves R or S.

In view of the fact that the actual amount of movement which is required of the pilot valves R. and S, the electro-magnets may be so constructed as to provide only a few thousandths of an inch movement of the armature or movable part of the magnetic structure and also since the pilot valve only is to be operated by the electro-magnet instead of the main valves proper, a relatively small amount of force is required to be exerted by the electro-magnets.

By referring to Fig. 1'7 it will be observed that the electrical control cap block 88 has a relatively large bore 83 extending from its upper end, into which may be assembled the electro-magnets 88 and 8|. The bore 83, being circular in cross section, facilitates the construction of the electromagnets by permitting them to be circular in cross section, again adapting the construction of the electrical portions of the valve structure by simple machining operations such as could be performed upon a lathe.

The electro-magnet 8| is constructed of a suitable iron core 84 circular in cross section and counter-bored with an annular groove 85, into armature 88 merely laid upon the upper end 0! the assembled core and coil will be attracted downwardly toward the core upon the energization of the coil 86. A bore 88 extends longitudinally through the central portion of the core body in such a location as to permit its alignment with one of the pilot valves S and a metallic pin 88 extends through this bore so that when the cap 88 is assembled upon the valve body A the pin 88 will rest upon the pilot valve .8 and, as

illustrated in Fig. 7, will hold the armature 88 in slightly spaced relation from the core 84. Then upon energization of the coil 86 the armature will be depressed against the normal upward thrust of the pilot valve S, causing the pilot valve S to be depressed in the same manner as though it had been operated by the manual control structure illustrated in Fig. 1.

The electro-magnet 82, which is disposed immediately below the electro-magnet 8|, is of substantially identical construction except that the mid portion 8| of the core of this magnet is provided first with a bore 82 alignable with the bore which may be seated a ring-like coil 86. The

central portion 81 of the core provides one leg of the magnetic path while the side walls of the core 84 provide the opposite leg so that a circular 88 so as to permit the passage of the pin 88 therethrough and, in addition, it is provided with a second bore 83 through which extends a second pin 84 adapted to be aligned with and rest upon the opposite pilot valve R. The armature plate 85 for the magnet 82 rests upon the upper surface of the core for this magnet and is held in spaced relation, as illustrated in Fig. 17, by the upward pressure exerted by the pilot valve R. until the coil 82 is energized, whereupon the pin 83 will be depressed and will actuate the pilot valve R in the same manner as if it had been operated by the manual control structure illus trated in Fig. 1. The armature plate 85 must, however, be provided with a relatively large opening 88, through which the pin 88 of the magnet 8| may extend, it being preferable that the opening 86 be sufficiently large to provide ample clearance about the body of the pin 88.

Tospace the two magnets 8| and 82 apart and to provide operating space for the armature 95, there is provided a spacer ring 81 of non-magnetic material, this ring being preferably formed in the shape of a cup, the side walls or flanges of which act as a spacer between the cores of the magnets 8| and 82, while the bottom of the cup acts as a, supporting shelf upon which the magnet 8| may rest. Preferably the mid section of the bottom of the cup is cut out to provide ample clearance through which the pin 88 may extend and facilitate the assembly of the magnetic structure in the cap body 88. The conductor wires for the respective magnets 8| and 82 are preferably led upwardly through a slot or longitudinal groove 88 formed along one side of each of the cores of the magnets 8| and 82. A corresponding slot or notch 88 is formed in the spacer ring 81, as shown in Fig. 20. A cover I88 may be employed to cover and enclose the upper end of the magnet structure, such cover being preferably of the same length and breadth as the cap body 88 and provided with a, central bore |8|, through which the conductor wires W may be led to permit their connection to the control circuits.

By referring particularly to Fig. 19 it will be observed that the armatures 88 and 85 may be prevented from rotating upon their cores by means of pilot pins I82, two of these being preterably provided for each armature set into the middle portion or mid leg of the cores of the respective magnets with which they are associated, The upper or projecting ends o'f'the pins pass through loosely fitting holes formed in the armatures. Thus the upward and downward movement of the armatures is in no wiseimpeded but rotation of the armatures, such as might bring" the armature 95111130 metallic Contact with the pin 99, is effectively prevented.

As pointed out hereinbefore, the cap body 80 may have integrally formed in its lower portion a hydraulic control structure such as that illustrated in Figs. 13 and 14 without interference with the operation of the electrical control since, as will be observed from an inspection of Fig. 16,; the pistons 73a and 14a engage the pilot valves R arid-S at one side of their centers while the operating pins 90 and 94 engage t vsame pilot valves on the opposite side of their centers, thus permitting the valve to be equipped with both magnetic and electrical controls. the event of a failure of the electrical system the hydraulic control could be used or vice versa.

On the other hand, if the hydraulic structure i's'not desired, the body 8'!) may be formed without the hydraulic structure therein. Thus it will be observed that by providing a standard set of main valve bodies and pilot valve assemblies and by providing a stock of manual control caps, a stock of hydraulic control caps and a stock of either combination magnetic and hydraulic or simple magnetic control caps, any desired assembly of valve operators may be made to suit a particular application of this valve structure to a hydraulic control problem.

While there has been shown and described the preferred embodiment of the present invention, the same is not to be limited to any of the details of construction shown and described herein, except as defined in the appended claims.

What is claimed as new is:

1. In a valve structure, a valve body block hav-- ing a pilot valve assembly bore extending from one surface thereof and having its axis disposed substantially centrally of said surface, a plurality of main valve bores formed in said block and disposed about said pilot valve bore, ports formed in said body, one for each of the main valve bores, the ports from the different valve bores extending to and communicating with the pilot valve bore at diflerent levels in said bore, a pilot valve assembly comprising a pilot valve body and a plurality of pilot valves carried thereby, said assembly being insertable into the pilot valve bore, and packing rings on said pilot valve body disposed at diiferent levels thereon and between the port levels for dividing the pilot valve bore into a plurality of chambers to prevent inter- 7 communication between the ports extending from different main valve bores.

2. In a valve structure, a valve body block having a pilot valve assembly bore extending from one surface thereof and having its axis disposed substantially centrally of said surface, a plurality of main valve bores formed in said block and disposed about said pilot valve bore, ports formed in said body, one for each of the main valve bores, the ports from the different valve bores extending to and communicating with the pilot valve bore at different levels in said bore, a pilot valve assembly comprising a pilot valve body and a plurality of pilot valves carried thereby, said assembly being insertable into the pilot valve bore, packing rings on said pilot valve body disposed at different levels thereon and between the port levels for dividing the pilot valve bore into a plurality of chambers to prevent interlqfiirhuniication between the ports extending from different main valve bores, and ports in said pilot'v'alve body, one for each of said pilot valves, te ports from each of the pilot valves colnlnun ating with a different one of said ehjmber's'. M I u 3. In a valve structure; a valve body block havf ing a pilot valve assembly bore extending from ",tlre're'of'and having its axis disposed y centrally r said surface; a Plural I am valve bores formed in said block and e about said pilot valve bore, a fluid inlet n said body through which fluid from a source of pressure may now into said body, a Inlet vaive assemm insertable into said pilot valve bore and including a plurality of pilot valves for controlling the flow of fluid to' the d'iiferent main valve bores, a port communicating with said pilot valve bore and with the fluid inlet in said body, and check valve interposed in said port to prevent return flow of fluid from said pilot valve bore.

4.1In a valve structure, a valve body, four valve bores extending from the surface thereof intothe body and each formed with a seat at an intermediate point, a cylindricalv'alve member fitting? in each" of said bores and having one end terminating in a frusto-conical portion to contact its valve seat, an inlet port in said body and adapted to be connected to a source of fluid under pressure and communicating with two of said valve bores above the valve seats, an exhaust port in said body adapted to be connected to an exhaust system and communicating with the other two of said valve bores above the valve seats, two operating ports formed in said valve body and each communicating with the bottom of one of the bores connected to pressure and the bottom of one of the bores connected to exhaust, means communicating the outer end of each of said valves to said inlet port, whereby inlet pressure seats the valves, and pilot valve means associated with said communicating means to remove inlet pressure from the outer end of a selected pair of valves including a pressure and exhaust valve and apply instead exhaust pressure, whereby the pressure on the inner end of the valves will cause the valve pair selectively to open.

5. In a valve structure, a valve body, four valve bores extending from the surface thereof into the body and each formed with a seat at an intermediate point, a cylindrical valve member fitting in each of said bores and having one end terminating in a, frusto-conical portion to contact its valve seat, an inlet port formed in said body and adapted to be connected to a source of fluid under pressure and communicating with two of said valve bores above the valve seats, an exhaust port in said body adapted to be connected to an exhaust system and communicating with the other two of said valve bores above the valve seats, two operating ports formed in said valve body and each communicating with the bottom of one of the bores connected to pressure and the bottom of one connected to exhaust, a cylindrical bore in said valve body having its lower end communicating with said inlet port, a pilot valve housing disposed in said bore and having two parallel stepped bores therethrough, four ports in said pilot valve housing spaced along the housing, one disposed on either side of the stepped portion of each of said stepped bores, means conmeeting the outer two of said pilot housing bores I m and said to. saidexhaust Y port, conduits providing communication between eachof the inner pjiqt hous j mainjvalves, fa drilled plug; inserted in the inner end of each of said steppedj pilot bores having a reduced inner endijto perinit new to its associated port, a movable .vaive element in each of saidwstepped bores having an enlarged headthat seats on the bore" step, whereby pressure fluid flows through said drilled plug and into the inner pilot housing bores to seat the main valves pilot. exhaustj p rts,

and is excluded from the whereby they unseat at the bore step and there after close off the associated drilled va1ve"p1ug exhaust pressure 16,111 a lp t adapted to retain a pilot vaive having two ele-.

ments movablea long parallelaxes, a valve .cap:

adapted to be secured to thevalve bo dy to cover saidpilot valve and having a pore.parallelto and means for selectively moving said movable pilot valve elements.

operated valve, a valve body" file of this patent:

the. cappin I surface and intersecting @a recess therein over shaft passing into saidvalve cap bore and hav- 25 ing' a portion fl'atted in the'region of the pilot 5 3 6 valve-elements, andihaving a reduced sectionthe pilot valve elements, a'rotatable 15 communicating the m ain valve bores only with;

ataa nother; portion, a. slotformed' said valve,"

cap through vsaid shaft "bore, and ai shim 4 in-'-. serted" in the slot to engage the reduced portion Administrath'zio the Estate or owe, Mdrtim} Deceased; I ,e p

, REFERENCES CIT I The'following references are of'record in-the UNITED STATES PATENTS :Mercier Feb. 3,1948: 

